I have a Dell machine and something happened and Windows XP Home was corrupted. I tried to run a repair, but that option was not available so I reformatted the hard drive and I'm trying to install a clean copy of XP Home SP2 on the machine using the Product Key on the sticker on the case, but I keep getting invalid product key. I don't have the original Dell XP Cd, so I'm just using a XP Home CD. Any ideas on the problem? Thanks